Heat wave arriving as 2 weather systems clash over Southern California

The weather system that’s blessed Southern California with cooler-than-average temperatures for the last week is leaving, but not without a fight, according to the National Weather Service.

A spinning low-pressure system about 300 miles west of Eureka is being pushed out by a high-pressure system and a heat wave that originated in Texas, said meteorologist Joe Dandrea.

The combination of the two has created an unusual situation between 10,000- and 20,000 feet in the air, Dandrea said. The two competing weather patterns are allowing monsoonal moisture that originated in the Gulf of Mexico to flow up from Arizona and could bring slight showers and thunderstorms to San Diego County and into the deserts through Wednesday, he said.

But it won’t last long, he said. The entire Southland will be in the grip of a heatwave by then, including Los Angeles and Ventura counties.

The hardest-hit areas will be traditional hot spots like Woodland Hills and Burbank, where temperatures by the weekend could top out at 103 and 98 degrees, respectively, said weather specialist Stuart Seto. Downtown Los Angeles will bake in above-average heat Saturday and Sunday, when temperatures could hit 91 degrees, Seto said.

The temperatures, though not record-breaking, are still about 10 degrees above average for this time of year, Seto said. The weather for the last week has been cooler than average, he added.

If Southern Californians need another reason to hit the beach this weekend, the water is also unusually warm, Seto said. The water at the Santa Monica Pier on Sunday was a tropical 74 degrees; it was 71 degrees in Marina del Rey, he said. The warmth of the waters is expected to persist through the week.

But the heat brings an increased risk of fire in the drought-parched mountains and hills. Though humidity is not expected to drop low enough to trigger wildfire warnings, years of drought and 10- to 20-mph winds expected this weekend can turn any spark into a dangerous fire, Seto said.

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